PB2382: EFFECTS OF ANTIFASCIN COMPOUNDS AGAINST LYMPHOMA CELLS IN VITRO
Authors: Ana María Hurtado López, Daniel Chedas, María José Sánchez de Las Matas Garre, Fátima Postigo-Corrales, Ana Albaladejo González, Asunción Beltrán Videla, Daniel Torres-Moreno, Ana Belén Arroyo-Rodríguez, José García-Solano, Pablo Conesa-Zamora, Gines Luengo-Gil
Journal: HemaSphere (2023)

Topic: 20. Lymphoma Biology & Translational Research Background: Fascin is a structural actin-binding protein that is essential for the formation of filopodia and other cellular cytoskeletal structures. It has been shown in numerous types of cancer that its overexpression negatively impacts patient survival since it is essential for cell migration and invasion. Accordingly, it has been shown in silico, in vitro and in vivo that treatment with antifascin agents can be an effective targeted pharmacological strategy in numerous types of cancer. Aims: 1- To analyze fascin expression in different histological subtypes of lymphoma and 2- to evaluate the effectiveness of antifascin compounds against different lymphoma cell lines. Methods: A pilot study including 55 FFPE tissue samples from lymphoma patients were retrospectively collected in our hospital. Tissue microarrays of each case was constructed in duplicate and immunohistochemistry for fascin was performed in an Autostainer. Fascin expression in tumors was evaluated and results were included in a SPSS database. Three antifascin compounds (imipramine, monastrol and NP-G2-044) were tested against three lymphoma cell lines: L-428, HD-LM-2 (positive expression of fascin, Hodgkin lymphoma cell line models) and U937 (negative expression of fascin, histiocytic lymphoma cell line model). In vitro evaluation included proliferation, migration, invasion and apoptosis in absence or presence of these compounds. Results: Expression was positive in 20 tissue samples and negative in 35. By subtypes, fascin was found positive in Hodgkin (6 cases of 13, 46%) and non-Hodgkin lymphoma including lymphoblastic (2 cases, 100%), NK (2 cases, 100%), MALT (4 cases of 6, 67%), mantle cell (3 cases of 9, 33%), and marginal zone (1 case of 3, 33%) lymphoma. Monastrol and imipramine reduced the viability of L-428 cell line in comparison to U937 (IC50 of imipramine: 70.7±5.4 vs 96.6±1.1µM, p<0.01; IC50 of monastrol: 38.1±5.6 vs 50.9±8.6µM, p<0.01, respectively), being monastrol more effective than imipramine. NP-G2-044 gave conflicting results and was less effective against proliferation of these cells. Imipramine was the compound more effective reducing migration in all cell lines at 1 and 10 µM, revealing that their ability to reduce cell migration is not only dependent of the inhibition of fascin, so there must be more molecular targets to explore. Migration inhibition was stronger in L-428 than in U937 (relative reduction to control: 33±9.9 vs 47.1±6.1 at 1µM imipramine (p<0.05), respectively; 20.3±4.8 vs 28.3±3.3 at 10µM imipramine (p<0.05), respectively). Western blot analysis revealed that treatment with imipramine at 50µM reduces fascin expression in L-428 (p<0.05). We are now evaluating the effectiveness of these compounds against invasion, apoptosis and further molecular analysis will be carried out to better understand the mechanisms of action of these drugs in vitro and in vivo. Summary/Conclusion: Fascin expression was detected in several types of lymphoma including Hodgkin, lymphoblastic, NK, MALT, mantle, and marginal zone lymphoma. Among evaluated compounds, imipramine appears to be the most promising inhibitor of proliferation and migration in fascin-overexpressing lymphoma cells. As might be expected, imipramine is less effective against cells without fascin. Imipramine could inhibit migration by both direct interaction with the protein and also by reducing the total concentration of fascin in the cell. Interestingly, our data highlight the therapeutic potential of these drugs that could be useful in the future to reduce the risk of distant relapses in lymphoma. This work was supported by the Spanish Foundation of Hematology and Hemotherapy (FEHH/Janssen fellowships, 2020). Keywords: Drug sensitivity, Lymphoma, Lymphoma therapy